Thanks, but that's not the only one I have that shoots like that, the 45-70s, both the BC and both Handis and the 45-120 BC shoot just as well, not with all loads, but for the most part, just about any cast bullet that's sized right for the bore, and the Nosler partition, Hornady RN and Speer FN make one hole 100yd groups.

My older 243 Ultra Varmint also likes the Federal ammo, both the fusion and the Power Shoks, they both shoot under 1", the Power Shoks shooting about half that.
Another that shoots that way is the 25-06 Ultra, although it has a bit of vertical stringing on 3rd, 4th and 5th shots, but I don't consider more than the first two rounds being important and they're touching or real close always, so I don't mess with it trying to get it to stay together, it's not broke.

Have fun on the fitting, many here have done it for the first time and were very happy with the results, others not wanting to spend the time and energy just sell the barrel and buy another, that DIY stuff isn't for everyone. But the Handiholic support group is always here to help out when ya need it, so don't be afraid to ask.
Read the FAQs and Help sticky, lots of good stuff in there, including barrel fitting info.

Tim